1. Field of the Invention
The invention relates to a method for initializing a network for wirelessly locating or determining the position of objects within a limited space. The subject matter of the present invention also includes a computer program and a machine-readable data storage medium for saving the computer program, by means of which the method according to the invention can be executed.
2. Description of the Related Art
The spatial location of moving objects by means of wireless or radio localization is known in the field of industrial factory buildings, production halls, factory premises or similar. Such objects can, on the one hand, be automatic industrial trucks (Automated Guided Vehicles—AGV) which are used in driverless transport systems. These industrial trucks are automatically driven and move along real or virtual guide lines without human intervention. In the fields of warehousing or industrial production, such a location can relate e.g. to steel products such as slabs or coils stored in a steelworks, wherein these objects can, however, also be autarkic robotic vehicles, fork lifts or similar. During this process, a one-dimensional location along the tracking e.g. of a crane, a two-dimensional location in an even plane or a spatial location of objects, e.g. in a three-dimensional stock management system, can take place.
Such a radio location system has become known from U.S. Pat. No. 6,133,876, which is referred to in its entirety by means of incorporation by reference, and relates to a method and a network arrangement for position determination by means of pulsed radio signals (known as an “Impulse Radio System”). As part of this, a first transceiver with a first clock and a second transceiver spaced from the first transceiver having a second clock are provided. A first reference clock impulse is generated using the first clock, and a first series of impulses is transmitted from the first transceiver by this reference clock impulse. This first series of impulses is received by the second transceiver and the second transceiver is synchronized based on these impulses. Using the second clock, a second reference clock impulse is generated from the second transceiver and thus a second series of impulses is transmitted from the second transceiver. The first transceiver receives this second series of impulses and uses them to carry out a synchronization. Based on this synchronization, a first reference clock impulse with a corresponding time delay is then generated and from this, the time difference between the first reference impulse and the delayed first reference impulse is determined, wherein this time difference specifies an overall running time of the first and second series of impulses.
A location system based on the ultra-wideband (UWB) signals and, correspondingly, based on the run-time or flight- time measurements arises from U.S. Pat. No. 7,873,099, in which a UWB receiver of a corresponding data communication network synchronizes receiver time information based on a received signal structure, wherein the time information is demodulated and wherein the demodulated time information is used to set a receiver clock. The receiver clock is adjusted based on information about the run-time delay by increasing the receiver clock value in order to balance out said run-time delay. The run-time delay is determined based on a known distance between the transmitter and receiver, wherein the transmitter and receiver can be part of a two-way connection, and wherein the run-time delay is determined by the measurement of round trip timing, i.e. by measuring the time which a data package in the data communication network requires for the transmission from transmitter to receiver and back.